TW201419076A - Display device including integrated touch panel and method of driving the same - Google Patents

Abstract

A method of driving a display device including an integrated touch panel, the method comprising: applying a plurality of sampling voltages to a plurality of electrodes of the integrated touch panel; determining a plurality of noise levels each of which is associated with a corresponding one of the plurality of sampling voltages; comparing the plurality of noise levels to a threshold level; and selecting a sampling voltage from the plurality of sampling voltages to use as a touch driving voltage based on the comparison of the plurality of noise levels to the threshold level; and applying the selected sampling voltage as the touch driving voltage to the plurality of electrodes.

Description

Display device with integrated touch panel and driving method thereof

The present disclosure relates to a display device, and more particularly to a display device having an integrated touch panel.

A touch panel is mounted on an image display device, such as a liquid crystal display device (LCD), a field emission display device (FED), a plasma display panel (PDP), an electroluminescence device (EL), an electrophoresis An input device in an display device (EPD) or the like for allowing a user to input predetermined information by pressing (or touching) a touch sensor in the touch screen when viewing the image display device.

Recently, in order to realize a thin mobile terminal, such as a smart phone, a laptop computer, etc., there is an increasing demand for an in-cell display device having an integrated touch panel, wherein the integrated touch panel is installed. The configuration components of the touch panel.

Hereinafter, an in-cell display device having an integrated touch panel and a noise level according to a touch driving voltage of the application will be described in conjunction with "1", "2A", and "2B".

"Fig. 1" is an integrated touch surface according to the conventional technology. A schematic diagram of a display device of a board. In particular, "Fig. 1" shows an in-cell self-capacitance display device having an integrated touch panel.

In FIG. 1 , an in-cell self-capacitance display device having an integrated touch panel according to the prior art includes a panel 10 and a touch integrated circuit (IC) 20, wherein the panel 10 forms a plurality of electrodes. 11 and a plurality of lines 12 connected to the electrodes 11, respectively.

For example, the touch integrated circuit 20 can sense a change in capacitance caused by a touch input applied to the electrodes 11 by a touch sensing unit 21 .

FIG. 2A and FIG. 2B are schematic diagrams showing a noise level of a touch driving voltage in a display device having an integrated touch panel according to the prior art.

In FIG. 2A, when a touch driving voltage VDDT of about 0.7 volts and about 0.85 volts is applied to a plurality of electrodes of a first display device having an integrated touch panel, a sense of touch in the capacitance changes. The measurement results have noise levels of approximately 25F and approximately 30F, respectively.

In FIG. 2B, when a touch driving voltage VDDT of about 0.7 volts and about 0.85 volts is applied to a plurality of electrodes of a second display device having a integrated touch panel, the sensing signals in the capacitors are respectively changed. There is a noise level of approximately 60F and approximately 30F.

Here, a touch sensitivity and a signal to noise ratio (Signal to Noise Ratio, SNR) proportional, the signal-to-noise ratio is the average of a sensed signal with one touch input plus the average of a sensed signal without a touch input divided by not having a touch input A maximum of one noise. Therefore, as the noise increases, the signal-to-noise ratio decreases and the touch sensitivity decreases.

This display device having an integrated touch panel has a variation in noise level, and the noise level of the display device having the integrated touch panel varies according to a driving condition. For example, the specific touch driving voltage can be an optimal value for minimizing the noise level in the display device having the integrated touch panel, and can be the largest in another display device having the integrated touch panel. A value that equalizes the noise level. Therefore, the noise level can be varied according to different display devices even when the same touch driving voltage is used.

In view of the above problems, embodiments of the present invention relate to a display device having an integrated touch panel and a driving method thereof. Thus, embodiments of the present invention are directed to a display device that overcomes one or more problems due to the limitations and disadvantages of the prior art.

An embodiment of the present invention provides a display device having an integrated touch panel. Here, a touch driving voltage VDDT suitable for a touch driving environment is applied to the touch panel.

Other advantages, objects, and features of the invention will be set forth in part in the description which follows, It will be apparent to those skilled in the art that the following description of the invention may be The objectives and other advantages of the invention will be realized and attained by the <RTI

In order to achieve the objectives and other advantages of the present invention and in accordance with an aspect of the present invention, a driving method of a display device having an integrated touch panel is provided. The driving method of the display device having the integrated touch panel includes: integration The plurality of electrodes of the touch panel provide a plurality of sampling voltages; determining a plurality of noise levels, each noise level being associated with a corresponding one of the sampling voltages; comparing the noise levels to a threshold level; A comparison of the noise level and the threshold level selects a sampling voltage from the sampling voltage to be used as a touch driving voltage; and a sampling voltage as a selection of the touch driving voltage is supplied to the electrodes.

In another aspect of the present invention, a driving method of a display device having an integrated touch panel is provided. The driving method of the display device having the integrated touch panel includes: providing a plurality of electrodes to the integrated touch panel a sampling voltage; determining a plurality of noise levels associated with the sampling voltages; determining a plurality of noise levels, each noise level being associated with a corresponding one of the sampling voltages; and comparing the noise levels to a threshold level Comparing; determining, in response to determining that all noise levels are greater than a threshold level: determining a sampled voltage associated with a minimum noise level from among the noise levels; and Level-dependent determined sampling voltage is selected as the touch driving voltage; and determining to determine that one of the sampling voltages is related to a certain noise level that is less than the threshold level: selecting the determined sampling voltage as the touch driving voltage; And applying a sampling voltage as a selection of the touch driving voltage to these electrodes.

In a further aspect of the present invention, a display device includes: an integrated touch panel having a plurality of electrodes; and a touch integrated circuit (IC), the touch integrated circuit comprising: a switching unit, A plurality of sampling voltages are applied to the electrodes of the integrated touch panel; a comparing unit is configured to: determine a plurality of noise levels, each noise level is related to a corresponding one of the sampling voltages; Comparing a threshold level; and selecting a sampling voltage from the sampling voltage to be used as a touch driving voltage according to the comparison of the noise level and the threshold level; and a touch sensing unit for touching A controlled drive voltage is supplied to these electrodes.

It is to be understood that the foregoing general description of the invention and the claims

10‧‧‧ panel

11‧‧‧Electrode

12‧‧‧ line

20‧‧‧Touch Integrated Circuit (IC)

21‧‧‧Touch sensing unit

100‧‧‧ panel

110‧‧‧Electrode

120‧‧‧ line

200‧‧‧Touch Integrated Circuit (IC)

210‧‧‧Variable sampling voltage generating unit

220‧‧‧Comparative unit

230‧‧‧Touch sensing unit

240‧‧‧Switch unit

VDDT‧‧‧ touch drive voltage

Fig. 1 is a schematic view of a display device having an integrated touch panel according to the prior art.

2A and 2B are schematic diagrams showing a noise level of a touch driving voltage in a display device having an integrated touch panel according to the prior art.

3 is a schematic diagram of a display device having an integrated touch panel according to an embodiment of the present invention.

Fig. 4 is a schematic view showing the operation of a display device having an integrated touch panel according to an embodiment of the present invention.

Reference will now be made in detail to the preferred embodiments embodiments embodiments In the following description, detailed descriptions of well-known functions or configurations related to the present document will be omitted when it is determined that unnecessary obscuring understanding of the gist of the present invention is made. The described processing steps and/or operations are performed as an example; however, the order of steps and/or operations is not limited to the description herein, except where steps and/or operations are required to occur in a particular order. Variations are known in the art. The same reference numerals denote the same elements. The selection of each component name used in the following description is only for convenience of writing the description, and thus can be different from that used in the actual product.

FIG. 3 is a schematic diagram of a display device having an integrated touch panel according to an embodiment of the present invention. In FIG. 3, a display device having an integrated touch panel may include a panel 100 and a touch integrated circuit (IC) 200. The panel 100 can have a touch panel (not shown) mounted therein, and the touch panel can be functionally configured to detect a touch position of a user. As an example, the touch panel can have an in-cell self-capacitance type.

The panel 100 may have a structure in which a liquid crystal layer is formed between two substrates. For example, a plurality of gate lines, a plurality of data lines crossing the gate lines, and a plurality of thin film transistors (TFTs) connected to the gate lines and the data lines may be formed at one of the bottoms of the panel 100. On the substrate. A plurality of pixels may be arranged in a matrix formed by crossing the gate lines with the data lines.

Additionally, panel 100 can include a plurality of electrodes 110 and a plurality of lines 120. The electrodes 110 function as a common electrode for driving a liquid crystal layer with a pixel electrode in each pixel and a function as a touch electrode when a common voltage is supplied to the electrodes to display an image. When a touch scan signal is provided to the electrode 110 to sense a touch, it is used to sense a touch position.

The line 120 is connected to the electrode 110 and the touch integrated circuit (IC) 200. For example, the line 120 can transmit the touch scan signal from the touch integrated circuit (IC) 200 to the electrode 110, and can transfer the change in the capacitance from the electrode 110 of the panel 100 to the touch integrated circuit (IC). 200.

In addition, the touch integrated circuit (IC) 200 supplies a touch driving voltage VDDT that minimizes a noise level to the electrode 110 and senses the touch position using a change in capacitance according to the touch driving voltage VDDT. For example, the touch integrated circuit (IC) 200 can include a variable sampling voltage generating unit 210 that generates a variable sampling voltage, and a comparing unit 220. The comparing unit 220 Using a signal received from the electrodes 110 due to the application of the variable sampling voltage to the electrodes 110, a noise level is repeatedly calculated (i.e., determined) based on the variable sampling voltage, and the noise level is predetermined Level comparison.

In addition, the touch integrated circuit (IC) 200 further includes a touch sensing unit 230 and a switching unit 240. The touch sensing unit 230 generates a touch driving voltage VDDT and uses the electrodes according to the touch driving voltage VDDT. The receiving unit receives the signal, and the sensing unit 240 senses the touch position according to a touch input. The switching unit 240 supplies the variable sampling voltage of the variable sampling voltage generating unit 210 or the touch driving voltage VDDT of the touch sensing unit 230 to the electrode 110. .

The variable sampling voltage generating unit 210 generates a plurality of sampling voltages for calculating (i.e., determining) the noise levels of the electrodes 110 according to different voltages and sequentially supplying the sampling voltages to the electrodes 110. In one embodiment of the present invention, the variable sampling voltage generating unit 210 generates each of these sampling voltages by arbitrarily selecting a sampling voltage from a voltage range. For example, these variable sampling voltages can be selected from a range of approximately 0.01 VDDT _threshold to approximately 1 VDDT _threshold . In one embodiment of the invention, the VDDT _threshold is a threshold voltage that requires touch of one of the sensing panels 100.

The comparison unit 220 uses the signals received from the electrodes 110 due to the applied sampling voltage, repeatedly calculates the noise level based on the sampled voltages, and compares the noise levels with the predetermined levels and stores the noise levels.

For example, when all calculated noise levels are higher than the predetermined power When the predetermined period of time is normal, the comparison unit 220 may store the noise level calculated for the predetermined period of time and may determine the sampling voltage corresponding to the noise level having a minimum value among the stored noise levels as the touch driving voltage VDDT. . In an embodiment of the present invention, the predetermined period of time may be a period of time corresponding to two frames of the panel 100 when the panel 100 is opened (eg, a period of one clock cycle of the panel) or may be It is a period of time from when the panel 100 is opened to when one of the users is touched. The comparison unit 220 can transmit information about the touch driving voltage VDDT to the touch sensing unit 230.

Furthermore, when a calculated (ie, determined) noise level is below the predetermined level for the predetermined period of time, the comparison unit 220 may store a noise level lower than the predetermined level and may correspond to the stored noise. The sampling voltage of the level is determined as the touch driving voltage VDDT. The comparison unit 220 can transmit information about the touch driving voltage VDDT to the touch sensing unit 230.

For example, the predetermined level may be a touch threshold level VDDT _threshold quarter to the touch threshold level value within a range of three quarters of the VDDT _threshold. In particular, the predetermined level may be one-half of the touch threshold level VDDT _threshold . In one embodiment of the present invention, the touch threshold value VDDT _threshold is a voltage level indicating whether the touch panel 100 is touched.

The touch sensing unit 230 generates the touch driving voltage VDDT according to the information from the comparing unit 220 and supplies the touch driving voltage VDDT to the electrode 110 through the switching unit 240. In an embodiment of the invention, the touch The sensing unit 230 generates the touch driving voltage VDDT each time the display device is in the touch driving mode. The touch sensing unit 230 can generate the touch driving voltage at least once during the touch driving mode of the display device. The touch sensing unit 230 receives the change in the capacitance according to the touch driving voltage VDDT and the touch input of the user through the switching unit 240 and the comparing unit 220, and uses the changes in the capacitance to sense the touch position of the user.

The switching unit 240 sequentially supplies the sampling voltages of the variable sampling voltage generating unit 210 to the electrodes 110 and transmits the noise levels of the electrodes 110 to the comparing unit 220 in accordance with the supplied sampling voltage. The switching unit 240 supplies the touch driving voltage VDDT of the touch sensing unit 230 to the electrode 110 and transmits the capacitance change in the electrodes 110 to the touch sensing unit 230 through the comparing unit 220 according to the touch driving voltage VDDT.

Further, when the switching unit 240 drives the panel 100 through a time sharing driving method during a touch driving mode, the sampling voltage corresponding to the noise level having the smallest value among the calculated (ie, determined) noise levels is determined. (ie, selected) as the touch driving voltage VDDT, and the determined sampling voltage is supplied to the electrodes 110. In one embodiment of the invention, during the time division driving method, the panel 100 operates in both a display driving mode and a touch driving mode within a frame (eg, a time period) of the panel 100. Alternatively, during a touch drive mode, when the panel 100 is driven by a time division method, the switching unit 240 will correspond to the predetermined level. The sampling voltage of the noise level is determined (ie, selected) as the touch driving voltage VDDT and the determined sampling voltage is supplied to the electrodes 110.

Although the variable sampling voltage generating unit 210, the comparing unit 220, and the switching unit 240 are formed inside the touch integrated circuit 200 of the display device having an integrated touch panel according to an embodiment of the present invention, the present invention In another embodiment, the variable sampling voltage generating unit 210, the comparing unit 220, and the switching unit 240 may be formed outside the touch integrated circuit 200. In addition, the display device having an integrated touch panel may include a display driving integrated circuit for display driving and the touch integrated circuit for touch driving.

In the display device with the integrated touch panel according to an embodiment of the invention, the noise level according to different touch driving voltages is detected from the electrodes during the touch sensing period, and corresponds to the minimum noise. The level voltage is selected as the touch drive voltage. As a result, the signal-to-noise ratio (SNR) of the touch sensing is improved and a higher touch sensitivity is obtained.

A driving method of a display device having an integrated touch panel according to an embodiment of the present invention will be described with reference to FIG. 4 . FIG. 4 is a schematic view showing the operation of a display device having an integrated touch panel according to an embodiment of the present invention.

In the "figure 4", a driving method of a display device having an integrated touch panel according to an embodiment of the present invention may include: the electricity to the panel Extremely repeatedly providing a variable sampling voltage, using the signals received from the electrodes to determine the noise level based on the variable sampling voltage and comparing the noise level to a predetermined level, and to have a predetermined noise level The sampling voltage corresponding to the minimum level noise level is selected as the touch driving voltage VDDT and the touch driving voltage VDDT is supplied to the electrodes when all of the determined noise levels are higher than the predetermined level for a predetermined period of time.

In addition, the driving method of the display device having the integrated touch panel according to an embodiment of the present invention may further include: selecting a sampling voltage corresponding to a noise level lower than the predetermined level as the touch driving voltage VDDT and when The touch driving voltage VDDT is supplied to the electrodes when a determined noise level is lower than the predetermined level for a predetermined period of time.

When the panel starts to operate, a step of driving the touch integrated circuit 200 in an open state is performed. For example, the touch integrated circuit 200 may have a closed state when the panel is not driven, and the touch integrated circuit 200 may have an open state when the display device is driven.

Next, in order to measure the noise of the electrodes according to different driving voltages, a step S2 of applying a variable sampling voltage to the electrodes of the panel and measuring the noise of the electrodes according to the variable sampling voltage is performed. For example, the variable sampling voltage can be in the range of approximately 0.01 VDDT _threshold to approximately 1 VDDT _threshold . The VDDT _threshold is to display whether a threshold voltage level of the touch panel 100 is.

Then, the noise level is determined based on the variable sampling voltage using noise received from the electrodes and the noise level is compared with a predetermined level, step S3. For example, the predetermined level may be a value within a range of about one-quarter of a touch threshold value VDDT _threshold to about three-quarters of the touch threshold level VDDT _threshold . In particular, the predetermined level may be approximately one-half of the touch threshold level VDDT _threshold .

Next, a step S4 of storing the determined noise level when the noise level is higher than a predetermined level, and a sampling voltage corresponding to the determined noise level when the determined noise level is lower than the predetermined level are performed It is determined as one of the touch driving voltages, step S8.

The user's touch input in the touch panel is sensed by a step S9 of providing the touch driving voltage VDDT to the electrodes. When the panel is driven by a time division method during a touch driving mode, a touch driving voltage can be supplied to the electrodes.

Then, after the step S4 of storing the determined noise level when the noise level is higher than the predetermined level, a step S5 of checking whether the step of measuring the noise according to the variable sampling voltage is within the predetermined time period is performed. For example, the predetermined period of time may be a period of time from when the panel 100 is opened to the two frames of the panel 100 or may be a period of time from when the panel is opened to receiving a touch input by a user.

When the step of measuring noise according to the variable sampling voltage is performed within this predetermined period of time, a step S6 of changing the variable sampling voltage is performed. For example, the variable sampling voltage can vary from about 0.01 VDDT _threshold to about 1 VDDT _threshold . Here, the VDDT _threshold is a threshold voltage indicating whether or not the panel 100 is touched.

Then, the step S2 of measuring the noise of the electrode according to the varying variable sampling voltage is performed again, and the steps S2 to S6 are repeatedly performed when the step of measuring the noise according to the variable variable sampling voltage is performed within the predetermined period of time.

After the steps S2 to S6 are repeatedly performed, when the step of performing measurement noise according to the changed variable sampling voltage exceeds a predetermined period of time, sampling corresponding to the noise level having the smallest level among the determined noise levels is performed The voltage is determined (ie, selected) as a step S7 of the touch driving voltage VDDT.

The touch input of the user in the touch panel is sensed by the step S9 of providing the touch driving voltage VDDT to the electrodes. The touch driving voltage can be supplied to the electrodes when the panel is driven by a time division method during a touch driving mode.

Therefore, in a display device with an integrated touch panel and a driving method thereof according to an embodiment of the present invention, a variable sampling voltage is supplied during a touch sensing period according to a noise level of different touch driving voltages. The electrodes are determined, and the voltage having the minimum noise level is determined as the touch driving voltage. In addition, the signal-to-noise ratio (SNR) is improved and a higher touch is achieved. Sensitivity.

A person skilled in the art will recognize that various changes and modifications can be made in the embodiments of the present invention without departing from the spirit and scope of the invention. Therefore, the present invention covers such changes and modifications as long as the changes and modifications of the present invention fall within the scope of the appended claims.

A number of examples have been described above. However, it will be understood that various modifications can be made. For example, if the described techniques are performed in a different order, and/or if elements in the described systems, structures, devices, or circuits are combined in various ways and/or replaced or supplemented with other elements or equivalents, Appropriate results can be obtained. Therefore, other implementations are within the scope of the following patent application.

Claims (21)

A driving method for a display device having an integrated touch panel, comprising: providing a plurality of sampling voltages to a plurality of electrodes of the integrated touch panel; determining a plurality of noise levels, each of the noise levels and the sampling voltages Corresponding to one correlation; comparing the noise level with a threshold level; selecting a sampling voltage from the sampling voltages for use as a touch according to the comparison of the noise levels and the threshold level Controlling the driving voltage; and providing the selected sampling voltage as the touch driving voltage to the electrodes. The method of driving a display device having a touch panel as the integration of the requested item 1, wherein such sampled voltage to a _threshold range from 0.01VDDT 1VDDT _threshold selected, one of which is the measured VDDT _threshold to sense the display device based The threshold level of the touch. The driving method of the display device with integrated touch panel according to claim 1, wherein the noise level is determined during a period from when the integrated touch panel is turned on. The driving method of the display device with integrated touch panel according to claim 3, wherein the time period corresponds to two frames of the integrated touch panel when the integrated touch panel is opened. The driving method of the display device with integrated touch panel according to claim 1, wherein the noise level is determined within a period from when the integrated touch panel is turned on to when a touch input is received. The driving method of the display device with integrated touch panel according to claim 1, wherein the selecting the sampling voltage comprises: determining that all the noise levels are greater than the threshold level; determining from among the noise levels a sample voltage associated with a minimum noise level; and the determined sample voltage associated with the minimum noise level is selected as the touch drive voltage. The driving method of the display device with integrated touch panel according to claim 1, wherein the selecting the sampling voltage comprises: determining one of the sampling voltages related to a certain noise level smaller than the threshold level; The determined sampling voltage is selected as the touch driving voltage. The driving method of the display device with the integrated touch panel as described in claim 1, wherein the providing the touch driving voltage comprises: when the integrated touch panel is driven by a time division method during a touch driving mode, Providing the touch driving voltage to the electrodes, wherein during the time dividing method, the integrated touch panel is in a display driving mode and the touch driving mode during one time period of the integrated touch panel Drive down. The driving method of the display device with integrated touch panel according to claim 1, wherein the threshold level is a quarter of a touch threshold level to four points of the touch threshold value Within a range of three, the touch threshold level indicates whether a touch input is received at the integrated touch panel. The driving method of the display device with integrated touch panel according to claim 1, wherein the threshold level is one-half of a touch threshold value, and the touch threshold value indicates whether The integrated touch panel receives a touch input. A driving method for a display device having an integrated touch panel, comprising: providing a plurality of sampling voltages to a plurality of electrodes of the integrated touch panel; determining a plurality of noise levels, each of the noise levels and the sampling voltages One of the associated ones; the noise level being compared to a threshold level; responsive to determining that all of the noise levels are greater than the threshold level: determining from a minimum of the noise levels a sampling voltage associated with the noise level; and selecting the determined sampling voltage associated with the minimum noise level as the touch driving voltage; responsive to determining one of the sampling voltages and one less than the threshold level Determining a noise level correlation: selecting the determined sampling voltage as the touch driving voltage; and providing the selected sampling voltage as the touch driving voltage to the electrodes. A display device includes: an integrated touch panel having a plurality of electrodes; and a touch integrated circuit (IC) comprising: a switching unit for supplying a plurality of sampling voltages to the electrodes of the integrated touch panel; a comparing unit for determining a plurality of noise levels, each of the noise levels and the sampling One of the voltages is associated with one; the noise level is compared to a threshold level; and a sample voltage is selected from the sampled voltages based on the comparison of the noise levels to the threshold level Used as a touch driving voltage; and a touch sensing unit for supplying the touch driving voltage to the electrodes. The display apparatus according to a request item 12, wherein such sampled voltage is selected from a range 0.01VDDT _threshold to 1VDDT _threshold, where the threshold is based VDDT _threshold level of one of the means to sense the touch of the display. The display device of claim 12, wherein the comparison unit determines the noise levels during a period of time when the integrated touch panel is turned on. The display device of claim 14, wherein the time period corresponds to two frames from the integrated touch panel when the integrated touch panel is opened. The video processing device of claim 12, wherein the comparing unit determines the noise levels for a period of time from when the integrated touch panel is opened to when a touch input is received. The display device of claim 12, wherein the comparing unit selects the sampling voltage to pass: determining that all of the noise levels are greater than the threshold level; determining from among the noise levels is related to a minimum noise level a sampling voltage; and determining the determined sampling voltage associated with the minimum noise level as the touch driving voltage. The display device of claim 12, wherein the comparing unit selects the sampling voltage to pass: determining one of the sampling voltages associated with a noise level less than the threshold level; and selecting the determined sampling voltage As the touch driving voltage. The display device of claim 12, wherein the touch sensing unit provides the touch driving voltage when the integrated touch panel is driven by a time division method during a touch driving mode, wherein the touch driving voltage is provided at the time During the dividing method, the integrated touch panel is driven in two modes of a display driving mode and the touch driving mode during a period of the integrated touch panel. The display device of claim 12, wherein the threshold level is within a range of a quarter of a touch threshold level to a three-quarters of the touch threshold level, the touch The control threshold level indicates whether a user has touched the integrated touch panel. The display device of claim 12, wherein the threshold level is one-half of a level of the touch threshold, the touch threshold level indicating whether a user has touched the integrated touch panel.